A checkpointing method and system that utilize a write back controller.
The system can include a first controller for implementing a first
function, wherein the first function comprises part of a checkpoint
operation and wherein the checkpoint operation comprises a series of
contiguous checkpoint cycles. The system can also include a second
controller, the second controller for implementing a second function,
wherein the second function comprises a write back operation from a first
memory location to a second memory location and wherein the write back
operation occurs before a checkpoint cycle ends. Information already at
the second memory location can be selectively written back to a third
memory location.